This stubs out enough to get https://athenacrisis.com/ far enough to
actually load :^)
(cherry picked from commit 52ccd69e49a26b5fd2747730e278503625eb71e7)
This is still missing a bunch of spec steps to construct the
audio node based on the parameters of the OscillatorNode, but it is at
least enough to construct an object to be able to add a basic test which
can get built upon as more is implemented.
An AudioNode is the fundamental building block used in 'Audio
Contexts'. In our immediate case, the audio node we are working towards
implementing is an oscillating source node.
